July Newsletter: Great Lakes Water Levels

July Newsletter: Great Lakes Water Levels

Fluctuations in Lake Michigan’s water levels can have a big impact, especially on shoreline homes and infrastructure. But most don’t understand the range of these fluctuations and how to prepare for them, sometimes leading to significant problems.

There are three different types of Great Lakes water level fluctuations; short-term storm events, annual fluctuations, and long-term fluctuations, which typically cover 10-20 year cycles.

The National Oceanic and Atmospheric Association (NOAA) and other organizations have been tracking Great Lakes water levels since 1918, so we have nearly 100 years of calibrated measurements from which to draw conclusions. However, in the context of the life of the Great Lakes, 100 years isn’t all that much, so it’s possible, and even likely, that water levels have exceeded the ranges recorded over the past century. The Great Lakes recently experienced a 15-year period of low water levels from 1999 to 2014. In January 2013, Lake Michigan hit an all-time record low and then rebounded shortly after, rising between 4-4.5 feet in just over three years. The current Lake Michigan water level is still about two feet below the record high level.

Marinas, docks, and shoreline infrastructure are designed with consideration for all-time high water levels, but rising water levels can still result in damage to aging or poorly-maintained components. And when Lake Michigan water levels rise, rivers also rise, creating problems for homes and properties along rivers as well.

Shoreline property owners are now dealing with water levels higher than they’ve seen in 10 or 15 years. They may have built homes according to the annual high water line, not considering the long-term fluctuations. Seawalls and shore protection built 20 years ago were often ignored, because the property owners had a false sense of security due to the low water levels. Now that water levels have risen above long term averages, aging and/or insufficient infrastructure has been exposed, leading to erosion and other issues.

The lesson here is that, when working on a Lake Michigan shoreline project, it’s important to consider not just recent water levels, but long-term record ranges, as well.

Shoreline Improvements

Abonmarche is currently assisting homeowners and communities with water level-related issues from Wilmette, Illinois, to Muskegon, Michigan.